Rebuilding and redistributing open-source software isn't a scam so long as you respect the license. I've noticed a new term gain traction among Android ROM developers- kang. So long as you're honest and upfront about what you are doing then kanging is fine.

I must say regarding Iron, it's one of the pieces of software I'm completely happy with. I've been using it for close to a year now, on all three platforms without any issues. I check back every now and again for updates and they seem very regular.